Re: [PATCH v4 10/19] iommu: Add set_platform_dma_ops iommu ops

[Jason Gunthorpe]

On Wed, Jan 04, 2023 at 08:57:16PM +0800, Lu Baolu wrote:

> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index de91dd88705b..4e35a9f94873 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -2163,6 +2163,17 @@ static int iommu_group_do_detach_device(struct device *dev, void *data)
>  	return 0;
>  }
>  
> +static int iommu_group_do_set_platform_dma(struct device *dev, void *data)
> +{
> +	const struct iommu_ops *ops = dev_iommu_ops(dev);
> +
> +	if (!ops->set_platform_dma_ops)
> +		return -EINVAL;
> +
> +	ops->set_platform_dma_ops(dev);
> +	return 0;
> +}
> +
>  static int __iommu_group_set_domain(struct iommu_group *group,
>  				    struct iommu_domain *new_domain)
>  {
> @@ -2177,10 +2188,14 @@ static int __iommu_group_set_domain(struct iommu_group *group,
>  	 * platform specific behavior.
>  	 */
>  	if (!new_domain) {
> -		if (WARN_ON(!group->domain->ops->detach_dev))
> -			return -EINVAL;

This should still have the WARN_ON..

if (WARN_ON(!group->domain->ops->detach_dev && !dev_iommu_ops(dev)->set_platform_dma_ops)

Jason